Young U.S. Pat. No. 2,040,540 discloses a metal shaft formed of sheet metal tubing which is tapered toward both ends, with the upper tapered section comprising the grip and covered by leather.
Lemmon U.S. Pat. No. 2,086,275 discloses both a wood shaft and a steel shaft, each of which includes three tapered sections, with one tapered section being the grip section, and the thickness of the walls of the tubular shafts causing a variation in the exact points of beginning and end of the three sections of the shaft, and the degree of the taper of the sections.
Barnhart U.S. Pat. No. 2,153,880 discloses a hollow metallic tube with no straight sections, and several of the sections having varying wall thicknesses.
Vickery U.S. Pat. No. 2,230,429 discloses a tubular metallic shaft having three cylindrical sections with adjacent sections joined at abruptly changing diameters.
Tennent et al U.S. Pat. No. 5,265,872 discloses a shaft formed of composite of polymers reinforced internally by fibers, and having a "modified hourglass" shape, with an intermediate cylindrical section being the base rod itself of from 6 to 12 inches in length.
Feche et al U.S. Pat. No. 5,316,299 discloses three shaft embodiments, each made of a composite material and each including a tapered grip section connected at the small diameter end thereof by a short connecting portion to a larger diameter upper end of (1) a downwardly diverging full shaft length section (first embodiment), (2) a cylindrical section (second embodiment), and (3) a downwardly converging section (third embodiment).
French publication nos. 2,670,120 and 2,670,121 disclose tapered shafts of composite material including bulging and contracting cylindrical sections. Publication 2,670,121 further discloses a bi-cone form.
Graman USA Inc. discloses a golf club including a graphite shaft with a, so-called, Triple Flexpoint System (TFS.TM.) having sections with variable tapered outer surfaces and constant tapered inner surfaces.
Paragon Sports discloses a golf club including a graphite shaft with two kickpoints (DKS), as the result of three progressively decreasing cylindrical sections.